A Quick Peek Inside Browns Ferry (Unit 1): March 25, 2011ATHENS, Alabama -- Following the nuclear disaster in Japan, officials at Browns Ferry Nuclear Plant in Athens, Ala., opened the doors to the media on Friday, March 25, 2011, to show off the plant's safety features. (The Huntsville Times/Michael Mercier)

The Reactor Core Isolation Coolant system on Unit 1 will direct water into the reactor to keep it cool in the event of a catastrophe.

HUNTSVILLE, Alabama -- All three nuclear reactors at the Browns Ferry plant near Athens were operating at 100 percent Friday according to federal regulators, providing power to keep at least some of this heat at bay.

But Browns Ferry's operator, the Tennessee Valley Authority, faces the same paradox every summer: the plants are designed to help meet the valley's power demand amid the swelter, but when it gets too hot the plants may have to scale back.

Under TVA's water discharge permits with the Alabama Department of Environmental Management, the water temperature downstream from the plant cannot be higher than upstream when the water reaches a temperature of 90 degrees.

With the addition of a new cooling tower, TVA has said it hopes its system won't have to power down.

Michael Bradley, a TVA spokesman said as of Friday things are running smoothly.

"So far this summer, we are not experiencing any impacts due to river temperatures," Bradley said. "Browns Ferry has not been impacted by river temperatures or environmental permit limits on river temperature. When necessary, we have been operating our cooling towers, which aid in cooling the water discharged back to the river."

David Lochbaum, a former engineer at Browns Ferry who now works with the Union of Concerned Scientists, said last week that nuclear power plants are about 33 percent efficient, so two-thirds of the waste heat they generate has to be cooled using water. Lochbaum said increasingly hot water in the Tennessee River places another potential burden on Browns Ferry operations.

Lochbaum was part of a conference call last week with area environmental advocates who said electricity generation poses an ongoing strain on water resources, especially in times of drought or the reduced rainfall levels being experienced in North Alabama this year.

A study by the River Network, released last week, found that it takes on average 40,000 gallons of fresh water to produce a megawatt of electricity. The water is used, polluted or consumed in making the electricity, said Wendy Wilson, national director of the River Network's energy and climate programs.

Wilson said a megawatt of electricity is generally what it takes to power a household for a month.

Browns Ferry has the capacity to generate 3,300 megawatts in the summer, according to TVA.

While the River Network and the Southern Alliance for Clean Energy both called for less water-intensive electricity production, such as wind and solar, the current system is stable, if somewhat challenged.

Bill Yell, spokesman for Huntsville Utilities said Friday that the local utility's communications with TVA indicate the electricity generating system is fine, but it's also near record load. Yell said Huntsville Utilities customers used 1,144 megawatts Friday, below the all-time record demand of 1,281 mega-watts. Yell said while Saturday's temperatures remained high, many businesses were not operating, which was expected to lower power demand.

Water use is also high and the Madison County Water Department, which gets its water from Huntsville Utilities, has advised its customers to conserve water due to the high temperatures and lack of rain.

Mitch Reid, program director for the Alabama Rivers Alliance, noted on last week's conference call that Alabama does not have a comprehensive water-use plan which sets out how waters users - from residents to power plants - will get they water they need. Reid said Alabama Gov. Robert Bentley has started taking steps in that direction, ordering state agencies to make recommendations by 2013 toward such a plan.

TVA's Bradley said the utility is required to have more electricity-generation capacity available than expected demand and the utility is ready if unexpected problems arise.

Even with the plans in plans, it will likely be a challenging summer.

"TVA's all-time summer was in August 2007 at 33,482 megawatts with an average temperature of 102," Bradley said. "We are expecting the peak over the next few days to be about 31,000 megawatts."